(1) Field of the Invention
The present invention relates to a contact arrangement in a housing including a cover, the housing and cover defining a battery chamber having an opening closable by the cover, the chamber having dimensions substantially corresponding to the dimensions of a button battery to be received in the chamber through the opening thereof, and the battery having a negative pole and a positive pole constituted, respectively, by a casing and a cover, the contact arrangement comprising two contact elements arranged within the battery chamber to contact the battery poles, and one of the contact elements being a pre-tensioned V-shaped spring having two legs arranged to be pressed apart against the tensioning bias of the spring by the battery upon insertion of the battery into the chamber through the opening thereof, one of the spring legs being arranged opposite the opening and biasing the inserted battery into a predetermined position in the chamber. Such arrangements are used particularly in in-ear hearing aids.
(2) Description of the Prior Art
A contact arrangement of this type has been disclosed, for example, in Swiss patent No. 528,198. In this known contact arrangement, the V-shaped contact spring is in contact with a center portion of an end face of the battery. When the battery has been inserted into the battery chamber and the cover has been closed, it is clamped between the contact spring and the cover, the other battery pole being in contact with a conducting plate in the cover. The cover is connected to the housing by a bayonet joint formed by bent ends of the V-shaped spring and a further spring.
This contact arrangement has the disadvantage that the two contact elements are arranged in two separate parts, which causes problems in connecting the springs to the conducting plate, which must be effected by additional contacts led through the bayonet joint. This produces a correspondingly large number of contact points, which becomes problematic when the contact arrangement is used in a low-voltage circuit, such as in hearing aids.
Another contact arrangement is known from PCT application No. WO 86/0619, published Nov. 20, 1986, which discloses a pivotal battery drawer holding the battery and requiring two separate spring contacts arranged separately in the battery chamber. One of the spring contacts is V-shaped. The disadvantage of this contact arrangement is the complex shape of the relatively large contacts and the complicated holders therefor. In addition, the pivotal arrangement of the battery drawer is structurally involved and requires extra space to permit pivoting of the drawer.